One of the largest studies ever conducted on maternal sleep and child brain development has found that women diagnosed with sleep disorders before or during pregnancy are significantly more likely to have children who develop long-term neurodevelopmental disorders. The research, drawn from a national cohort of nearly two million births in South Korea, suggests that a mother’s sleep health may be a far more important and modifiable factor in her child’s neurological future than previously appreciated. The findings, published in the Journal of Clinical Sleep Medicine, arrive at a moment when clinicians and public health officials are increasingly focused on the prenatal environment as a determinant of lifelong health.
The study, led by Tak Kyu Oh and In-Ae Song of Seoul National University Bundang Hospital, took advantage of South Korea’s comprehensive National Health Insurance Service database, which captures virtually all medical encounters for the country’s population. The researchers identified every live birth between January 1, 2008, and December 31, 2012, ultimately including 1,993,494 children in the analysis. Because the national health system records diagnoses using the International Classification of Diseases, the team could track both maternal sleep disorder diagnoses and childhood neurodevelopmental outcomes over a follow-up period extending as far as fifteen years, through the end of 2023.
Maternal sleep disorder exposure was defined by specific diagnostic codes covering the major categories of sleep pathology, including insomnia, sleep-related breathing disorders such as obstructive sleep apnea, and sleep movement disorders including restless legs syndrome. Crucially, the researchers distinguished between two timing windows. A disorder was classified as pre-last-menstrual-period if it was diagnosed during a one-year lookback period before the estimated start of pregnancy, and as pregnancy-onset if it was first identified after conception. This temporal separation allowed the team to ask whether the association differed depending on when the sleep disturbance emerged, a question that carries real biological significance because the mechanisms by which maternal physiology shapes fetal brain development change across gestation.
Of the nearly two million children in the full cohort, 33,229, or about 1.7 percent, were born to mothers with a diagnosed sleep disorder. To ensure that any observed association was not simply explained by differences in maternal age, income, comorbidities, or obstetric characteristics, the investigators used propensity-score matching, a statistical technique that pairs each exposed child with comparable unexposed children. The matched analysis ultimately compared 33,183 children of mothers with sleep disorders against 160,131 unexposed children, creating a balanced comparison in which the two groups resembled each other on the measured confounding variables.
The headline result was striking. Children whose mothers had a sleep disorder before or during pregnancy faced a 36 percent higher hazard of being diagnosed with a long-term neurodevelopmental disorder, defined broadly by ICD-10 codes F70 through F95, a range that encompasses intellectual disabilities, developmental speech and language disorders, autism spectrum conditions, attention-deficit/hyperactivity disorder, and behavioral and emotional disorders of childhood. The hazard ratio of 1.36, with a 95 percent confidence interval of 1.32 to 1.41, was highly statistically significant. In absolute terms, the finding means that among children otherwise similar in their measured characteristics, those born to mothers with sleep disorders accumulated neurodevelopmental diagnoses at a measurably faster rate over the years of follow-up.
The timing analysis added an intriguing layer. Sleep disorders that predated pregnancy were associated with a hazard ratio of 1.31, while disorders first diagnosed during pregnancy carried a hazard ratio of 1.18. Both were significant, but the somewhat stronger association for pre-existing sleep problems hints that chronic sleep pathology may reflect a longer-lasting physiological burden, or perhaps that women with persistent sleep disorders differ in other unmeasured ways that influence fetal development. The subtype analyses were equally revealing. Maternal insomnia was associated with a 28 percent increase in risk, sleep apnea with a 32 percent increase, and restless legs syndrome with the largest elevation of all, a 48 percent increase, though the confidence interval for the latter was wider, spanning 1.18 to 1.86, reflecting the smaller number of affected mothers.
Why might a mother’s sleepless nights echo through her child’s developing brain? The authors and the broader literature point to several plausible biological pathways. Sleep deprivation and fragmented sleep activate the maternal stress axis, elevating cortisol and other glucocorticoids that can cross the placenta and influence fetal neurodevelopment. Animal studies cited in the paper show that maternal sleep deprivation aggravates neurobehavioral abnormalities, promotes inflammation, and impairs synaptic function in offspring, and that it inhibits hippocampal neurogenesis in young animals through inflammatory signaling. Sleep apnea introduces a second mechanism: intermittent hypoxia, in which repeated drops in blood oxygen overnight may deprive the fetus of adequate oxygenation during critical windows of brain growth. Disrupted circadian rhythms may also matter, since melatonin, a hormone governed by the sleep-wake cycle, plays documented roles in embryonic and fetal development.
The study’s design merits both praise and caution. On the strength side, its sheer scale is nearly unmatched in this field; most prior investigations of prenatal sleep and child outcomes, including a prospective analysis of prenatal sleep health and offspring ADHD symptoms in the American ECHO cohort, involved hundreds or thousands of participants rather than millions. The fifteen-year follow-up window captures diagnoses that emerge well beyond early childhood, and the propensity-score approach, a method rooted in the classic work of Rosenbaum and Rubin, guards against the most obvious forms of confounding. The researchers also followed STROBE reporting guidelines for observational studies, and the protocol received ethics approval from Seoul National University Bundang Hospital and the National Health Insurance Service, with de-identified data exempt from individual informed consent under South Korean regulations.
Nevertheless, the authors and independent observers would be quick to note that an observational study of this kind cannot prove causation. Sleep disorders in mothers may be markers of underlying mental health conditions, chronic inflammation, obesity, or medication exposure, some of which may be imperfectly captured in claims data. Diagnostic codes depend on clinical recognition, meaning that milder sleep problems in some women may go unrecorded, potentially biasing estimates toward the null. Conversely, mothers with diagnosed sleep disorders may simply interact with the health system more often, increasing the chance that subtle developmental issues in their children are noticed and coded. The researchers’ use of propensity matching mitigates but cannot eliminate these concerns, and residual confounding remains an unavoidable limitation of any non-randomized design.
Even with those caveats, the public health implications are considerable. Sleep disorders are among the most common and most treatable conditions affecting women of childbearing age, and previous meta-analytic work has shown that poor sleep quality during pregnancy is widespread. If the association observed here reflects even a partially causal relationship, then screening for insomnia, restless legs syndrome, and sleep apnea in women planning pregnancy, and treating these conditions effectively before conception and throughout gestation, could represent a low-risk, high-value intervention for the next generation’s brain health. The study’s authors emphasize exactly this point, arguing that early identification and management of sleep disturbances in women of childbearing age may help mitigate neurodevelopmental risks in their children. As the evidence base linking maternal sleep to offspring outcomes continues to grow, sleep may soon earn a place alongside nutrition, smoking, and alcohol as a core pillar of preconception and prenatal care, a shift that could reshape clinical guidelines and, potentially, the developmental trajectories of millions of children worldwide.
Subject of Research: Association between maternal sleep disorders before or during pregnancy and long-term neurodevelopmental disorders in offspring
Article Title: Associations between maternal sleep disorders and long-term neurodevelopmental disorders in children: evidence from a national cohort of 1.9 million births
Article References: Oh, T. K., & Song, I.-A. (2026). Associations between maternal sleep disorders and long-term neurodevelopmental disorders in children: evidence from a national cohort of 1.9 million births. Journal of Clinical Sleep Medicine, 22(1), Article 177. https://doi.org/10.1007/s44470-026-00122-7
Image Credits: AI Generated
DOI: 10.1007/s44470-026-00122-7
Keywords: maternal sleep disorders, pregnancy, neurodevelopmental disorders, insomnia, sleep apnea, restless legs syndrome, cohort study, South Korea, child brain development, prenatal health, epidemiology, Journal of Clinical Sleep Medicine
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Tags: child brain developmentchild neurodevelopmental risksCohort studyepidemiologyimpact of maternal sleep on child neurodevelopmentinsomniaJournal of Clinical Sleep Medicinelong-term child developmental outcomesmaternal health and child brain developmentmaternal sleep disordersmaternal sleep disorders during pregnancymodifiable prenatal risk factorsnational cohort sleep studyneurodevelopmental disorder preventionNeurodevelopmental DisordersPregnancyprenatal healthprenatal sleep healthrestless legs syndromeSleep apneasleep disorder diagnosis in pregnancysleep health and lifelong child healthSouth KoreaSouth Korea birth cohort study
